<!DOCTYPE html>
<html lang="en">
<head>
    <meta charset="UTF-8">
    <title>10.debug</title>
</head>
<body>

</body>

<script type="text/javascript">

    alert(d);

    var a = 10;

    var b = "hello";

    c = true;

    function fun(){
        alert("hello");
    }

    var d = 35;

</script>
</html>